Helicobacter pylori tissue test vs. blood test: Why do results differ for one in five people? [Health Check]

[Financial News] One in five Korean adults was found to have inconsistent results between a Helicobacter pylori tissue test and a blood test. Helicobacter pylori, which is responsible for 90% of stomach cancer cases, is known to raise the risk of stomach cancer by as much as 10 times in infected people compared with those who are not infected, underscoring the importance of accurate diagnosis and early eradication treatment.
Helicobacter pylori is a spiral-shaped bacterium that can survive even in the stomach's acidic environment. Once infected, it can lead from gastritis to stomach ulcers, duodenal ulcers, and eventually stomach cancer. It is believed to cause 90% of all stomach cancer cases, and infected people face a 2 to 10 times higher risk than uninfected people.
Although the domestic infection rate is declining, it remains high. According to a multicenter study conducted in 2016 and 2017 at 10 university hospitals and health screening centers in Korea, 43.9% of 16,885 participants tested positive for Helicobacter pylori antibodies. That figure has steadily fallen from 66.9% in 1998 and 54.4% in 2011. However, medical demand has increased. HIRA data show that the number of patients receiving treatment related to Helicobacter pylori rose from 22,000 in 2014 to 73,000 in 2024, an increase of about 3.3 times.
Diagnostic methods are divided into noninvasive and invasive approaches. Blood, stool and breath tests are noninvasive methods that can check for infection without endoscopy, while tissue biopsy through endoscopy allows for a more accurate confirmation.
Lee Sun-young, a professor of gastroenterology at Konkuk University Medical Center, has focused on the problem of discrepancies between testing methods. After analyzing 872 people who underwent Helicobacter pylori testing, she found that 18.1% of Korean adults had inconsistent results between tissue tests and blood tests. In particular, 145 people tested negative on the tissue test but positive on the blood test.

Professor Lee said, "Because Helicobacter pylori is not evenly distributed across the stomach lining, a single test has limitations in making a clear distinction." She added, "Using a noninvasive urea breath test or stool test alongside it can help improve diagnostic accuracy."
Once the bacterium is confirmed, patients can undergo eradication therapy using antibiotics and acid suppressants together. Successful eradication lowers the recurrence rate of stomach ulcers and also reduces the long-term risk of stomach cancer. Preventing infection in the first place starts with hygiene. Helicobacter pylori is mainly transmitted through the oral-fecal route or contaminated water and food, so people should pay close attention to handwashing and personal hygiene, especially in group-living settings or environments where eating out is common.
Professor Lee has been recognized for consistently publishing research findings on the diagnosis and eradication treatment of Helicobacter pylori over the past 20 years, and she now serves as the only Korean editor of the international journal Helicobacter.



[email protected] Reporter Jeong Myeong-jin Reporter